Modular flat panel display unit

ABSTRACT

Modular digital display apparatus is described having a panel enclosure within which is mounted a display panel, the panel enclosure being provided with a panel connector for receiving panel write signals, the apparatus comprising an interface module having a housing that is mechanically mateable with the first enclosure to form a unit and provided with an input connector for receiving via a flying lead an input display signal defining an image to be displayed and a connector for direct electrical connection to the panel connector. The interface module including processing circuitry for receiving the input display signal and processing it into panel write signals for displaying the image on the display panel.

FIELD OF THE INVENTION

[0001] The invention relates to display devices and, more particularly,to a modular flat panel display unit.

BACKGROUND OF THE INVENTION

[0002] With improvements in display technology, flat panel displaydevices have become more commonplace for desktop computers in officeenvironments and are also finding greater application to televisions andvideo monitors.

[0003] Typically, such devices comprise a cabinet which is generallysimilar to those used for CRT monitors, although of course with a muchshallower profile. Within the cabinet is contained the LCD display panelitself, its associated backlight and inverter board and an interfaceboard of some kind. Often, the unit will be powered from an externalAC/DC adapter.

[0004] The role of the interface board is to convert analog or digitalsignals received at signal input connector—such as a standard VGA analogoutput from a personal computer for instance—into a form that can beused to drive the LCD panel. Usually provided on the interface board isthe complex electronics required for high speed analog to digital andframe rate conversion together with a device known as a scaler.

[0005] The scaler is required because the LCD panel is pixelated, ie itcomprises a fixed number of display pixels in fixed positions. The inputdisplay signal itself however may be organised in a display frame with adifferent number of pixels. It may therefore be required to convert theresolution of the input signal for use with the resolution of the LCDdisplay panel itself. Also usually provided is functionality for powermanagement of the device and for on-screen display features that allowdisplay for instance of visible scales for brightness and contrastadjustments. An example of the type of electronics usually provided onthe interface board can be found described in U.S. Pat. No. 5,953,074.

[0006] The problem with this conventional configuration is that thecomplexity of this high speed signal processing functionality addssignificantly to the cost of the display device. However, many of thefunctions provided are not required by all users. For instance, manyusers may find it perfectly adequate to have a display device that onlyoperates at a single resolution, that of the display panel, andtherefore would not require the scaler.

[0007] Similarly, digital-only video interfaces are becomingincreasingly proposed and used and therefore the analog to digital andframe rate conversion may no longer be needed in all applications whilston the other hand, it may be necessary to provide a digital interface ofsome kind to receive the input signals. Other users may find it usefulto have an analog video input for receiving signal directly from a VCRfor instance, rather than or in addition to a VGA input, or a wirelessinput in accordance with evolving wireless connection standards.

[0008] To address similar problems, a variety of modular display deviceshave been proposed. For instance, DE-29705122 U1 proposes a flat screenmonitor having a universal mounting and additional modules. In thedevice proposed, a basic LCD module can be connected directly to theoutput of appropriate graphics cards and is supplied with power viathese cards. An optional analog to digital converter is contained in apositioning foot, which also contains a power supply for the basic LCDmodule device.

[0009] U.S. Pat. No. 4,969,046 describes a modular television apparatusincluding a video display module, a tuner module and a power supplymodule that are releasably combineable in a variety of combinations.

[0010] An << in PC << LCD video controller card designed forinstallation with a PC is available from Sage Inc. Such a card includesa graphics accelerator as well as providing digital signal and powersupply outputs for driving LCD panels.

[0011] Whilst such devices, if implemented as described, would be nodoubt generally satisfactory in their operation, it is considered thatthey do not address all of the problems that arise when developing amodular flat panel display unit that is manufacturable at low cost andthat meets the complex set of regulatory and other requirements placedupon a commercially available device.

[0012] This invention is directed to providing a modular flat paneldisplay architecture that provides both flexibility in the functionalitythat can be provided and in the components that can be used.

SUMMARY OF THE INVENTION

[0013] In brief, this is achieved by a modular digital display apparatushaving a panel enclosure within which is mounted a display panel, thepanel enclosure being provided with a panel connector for receivingpanel write signals, the apparatus comprising an interface module havinga housing that is mechanically mateable with the first enclosure to forma unit and provided with an input connector for receiving via a flyinglead an input display signal defining an image to be displayed and aconnector for direct electrical connection to the panel connector, theinterface module including processing circuitry for receiving the inputdisplay signal and processing it into panel write signals for displayingthe image on the display panel.

[0014] The panel enclosure can be arranged to present an identifier thatcan be read by the processing circuitry so as to enable parameters ofthe display device to be retrieved and used in the processing of thedisplay signal. In one embodiment, the panel enclosure comprises aregister that is readable via the panel connector, the identifier beingin the form of a value stored in the register although many other formsof mechanical and electrical identifiers would be possible.

[0015] This enables the need for the manufacturer to source differenttypes of display panel components to be accomodated within the modulararchitecture. Usually, the manufacturer of the display will buy thedisplay panels from another supplier and the detailed designs may varyas between different suppliers. Even if the manufacturer of the displayalso manufactures the display panel component then the design andqualification of the display panel may evolve over time and there may bea need to somehow isolate changes in the details of the panel fromchanges in the design of modular electronic functional blocks.

[0016] The processing circuitry can for instance comprise on screendisplay circuitry and in this case, the interface module advantageouslyincludes a surface provided with one or more externally accessibleswitches linked to the on screen display circuitry for enabling a userto adjust display parameters.

[0017] To enable the device to be used with conventional personalcomputer systems, the input connector is a VGA connector, the processingcircuitry in this case including an analog to digital converter.

BRIEF DESCRIPTION OF THE INVENTION

[0018] A flat panel display unit embodying the invention will now bedescribed, by way of non-limiting example, with reference to theaccompanying drawings, in which

[0019]FIG. 1 is a schematic block diagram showing the main functionalcomponents of a flat panel display unit;

[0020]FIG. 2 is sectional view showing the mechanical configuration ofthe unit;

[0021]FIG. 3 is a rear view of the unit.

BEST MODE OF CARRYING OUT THE INVENTION

[0022]FIG. 1 is a schematic diagram showing the main functionalcomponents of a modular flat panel display unit in accordance with theinvention. In FIG. 1 the broken lines denote the boundaries of thedifferent mechanical enclosures.

[0023] The device comprises a first set of components that are locatedwithin a panel enclosure 100. Panel enclosure 100 is of a shallowrectangular shape and includes the display panel itself 110 with itsassociated backlight and inverter 120. A RFI-free connector 130 isprovided to the rear of panel enclosure 100 for receiving the panelwrite signals that control the display of images on the panel. Digitaldata conversion circuit 125 is provided for converting input TTL signalsinto the LVDS signals used by the panel.

[0024] A mechanically separate interface module 140 contains variousvideo signal processing components including scaler circuit 150 forchanging the pixel resolution of a digitally encoded image, a VGAinterface 160 including a standard VGA input connector for receiving aninput signal via a flying lead from a computer system unit and analog todigital conversion and frame rate conversion circuitry denoted at 165.The interface module 140 is provided with a connector 131 correspondingto connector 130 and allowing interaction between the components mountedwithin panel enclosure 100 and those mounted within the interface module140. A RAM 175 for storing a frame buffer is provided that is used byscaler 150 for temporarily storing the image displayed on the screen toenable Frame Rate Conversion.

[0025] Within the functionality provided in interface module part 140 isa microcontroller 185 which includes firmware that serves to manage thefunctions of the monitor, such as video timing, communication withscaler 150, and the generation of menus and other visible indications onthe display screen, in particular in response to the modification ofvarious parameters of the screen such as brightness, contrast etc - afunction generally referred to as on screen display (OSD). The user canadjust display parameters through OSD using buttons that are presentedto the exterior of the interface module, denoted as user interface 190.

[0026] Interface module 140 also includes a DDC ROM 195 which storesstandardized Extended Display Identification Data information and makesit available to a host computer via VGA interface in accordance with thewell known Display Data Channel standards.

[0027] In this embodiment, power control circuits 180, which includesuitable DC-DC converters are located with the interface module part140. Power for the display panel itself is passed to panel enclosure 100via connector 130.

[0028] The general operation of these components is well known in theart and will not be described in any more detail here.

[0029] The purpose of dividing the electronic functionality betweenpanel enclosure 100 and the interface module 140 to introduce modularityto the design. This This modularity can be implemented at themanufacturing or at the end user level. The electronic components thatare mounted in panel enclosure 100 are those that are associatedspecifically with the operation of the display panel itself and so willalways be required whatever the application of the unit. The componentspresent in interface module 140 are those that are optional in the sensethat not all customers will require them or they may be subject tovariation according to the geographical market for which the unit isintended, technological trends or changes in applicable technicalstandards.

[0030] Since unit 140 is separately manufactured from unit 100, theconfiguration allows great flexibility in the manufacturing arrangementspossible. Indeed, interface module 140 may be manufactured in adifferent place and in different quantities from panel unit 100, andpossibly even by different manufacturers.

[0031] It is possible, but not essential that the interface module 140be interchangeable at the point of use, although this is not excluded.Depending on the manufacturing and supply chain strategy adopted, Theconnectors 130 and 131 can be selected to support different design andcost constraints.

[0032]FIG. 2 shows in a sectional view one example of the physicalconfiguration of the unit in an exemplary embodiment. FIG. 3 is a rearview of the unit. As can be seen in FIG. 2 the panel enclosure 100 andthe interface module 140 are mechanically mateable to form a singleunit. In particular in the design shown in FIG. 2, interface module 140includes a surface 200 upon which is provided connector 131. Surface 200engages the rear surface of the panel enclosure 100 so that connectors130 and 131 are completely enclosed in the assembled unit.

[0033] This intimate mechanical and electrical mating of the two partshas advantages in limiting RFI radiation from the device, which would begreatly increased if the two enclosures were to be separated and linkedfor instance by a cable. The RFI seal can be improved by the use of asuitable gasket disposed between module 140 and enclosure 100.

[0034] In this embodiment, a circuit board 210 supporting the componentsof interface module 140 is mounted vertically within the module 140 andconnector 131 is directly mounted on the circuit board. As can be seenin FIG. 2, the interface module is stepped in order to allow the buttonsto be presented at the front surface of the display unit.

[0035] The unit is designed to be powered using an external AC/DC powersupply adapter of known type, the interface module part 140 including aconnector for connection to the adapter.

[0036] The panel enclosure 100 also comprises a register 170 thatpresents a simple identifier n the form of a value stored in theregister that can be read by the circuitry in the interface module inorder to enable the type of flat panel to be known and themicrocontroller on the interface module to be properly configured.

[0037] This addresses the need for the manufacturer of the unit toaccommodate different types of display panel components within a modulararchitecture. Usually, the manufacturer of the display will buy thedisplay panels from another supplier and the detailed designs may varyas between different suppliers. Even if the manufacturer of the displayalso manufactures the display panel component then the design of thedisplay panel may evolve over time and there may be a need to isolatechanges in the details of the panel from changes in the design ofmodular electronic functional blocks. The identifier stored in register170 provides a means for the microcontroller within interface modulepart 140 to discover which type of panel is present in the panelenclosure and to adapt their parameters accordingly.

[0038] Although a specific embodiment of the invention has beendescribed that employs one possible configuration of the interfacemodule 140, the invention is not to be limited to the specificarrangement so described and it will be appreciated that many otherconfigurations are possible. For instance, interface module 140 couldinclude any number of analog or digital inputs with their respectiveconnectors. Additional functionality could also be added to interfacemodule 140 for instance an amplifier could be integrated into the moduleand connections provided for speakers and/or microphone and a camera ifrequired, the interface module could configured as a USB hub to allowconnections to keyboard and/mouse device and control of the monitoritself via a USB connection. If the display panel incorporates a touchscrenn, then associated touch screen controller could be incorporatedinto the module.

[0039] The invention is limited therefore only by the claims. The claimsthemselves are intended to indicate the periphery of the claimedinvention and are intended to be interpreted as broadly as the languageitself allows, rather than being interpreted as claiming only theexemplary embodiment disclosed by the specification.

1. Modular digital display apparatus having a panel enclosure withinwhich is mounted a display panel, the panel enclosure being providedwith a panel connector for receiving panel write signals, the apparatuscomprising an interface module having a housing that is mechanicallymateable with the first enclosure to form a unit and provided with aninput connector for receiving via a flying lead an input display signaldefining an image to be displayed and a connector for direct electricalconnection to the panel connector, the interface module includingprocessing circuitry for receiving the input display signal andprocessing it into panel write signals for displaying the image on thedisplay panel.
 2. A display apparatus as claimed in claim 1 wherein thepanel enclosure is arranged to present an identifier that can be read bythe processing circuitry so as to enable parameters of the display panelto be retrieved and used in the processing of the display signal. 3.Modular display apparatus as claimed in claim 1 wherein the processingcircuitry comprises a scaler for changing the pixel resolution of theimage.
 4. Modular display apparatus as claimed in claim 1 wherein theprocessing circuitry includes on screen display circuitry.
 5. Modulardisplay apparatus as claimed in claim 3 wherein the interface modulehousing includes a surface provided with one or more externallyaccessible switches linked to the on screen display circuitry forenabling a user to adjust display parameters.
 6. Modular displayapparatus as claimed in claim 1 wherein the input connector is a VGAconnector, the processing circuitry including an analog to digitalconverter.
 7. Modular display apparatus as claimed in claim 1 whereinthe panel enclosure comprises a register that is readable via the panelconnector, the identifier being in the form of a value stored in theregister.
 8. Modular display apparatus as claimed in claim 1 comprisingan external AC/DC power supply adapter, the interface module including aconnector for connection to the power supply module and a DC-DCconverter and being arranged to supply power to the panel via the panelconnector.
 9. Modular display apparatus as claimed in claim 1 whereinthe panel enclosure comprises an inverter and a backlight.